Assignment Discovery Photosynthesis For Kids

Table of Contents

What is Photosynthesis? | Leaves and Leaf Structure | The Nature of Light | Chlorophyll and Accessory Pigments

The structure of the chloroplast and photosynthetic membranes| Stages of Photosynthesis |The Light Reactions

Dark Reaction |C-4 Pathway | The Carbon Cycle | Learning Objectives | Terms | Review Questions | Links

What is Photosynthesis?| Back to Top

Image from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com), used with permission.

Leaves and Leaf Structure | Back to Top

Image from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com), used with permission.

(SEM x3,520). This image is copyright Dennis Kunkel at www.DennisKunkel.com, used with permission.

Image from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com), used with permission.

Image from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com), used with permission.

Chlorophyll and Accessory Pigments | Back to Top

Image from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com), used with permission.

The above image is from http://www.nyu.edu:80/pages/mathmol/library/photo.

The above image is from http://www.nyu.edu:80/pages/mathmol/library/photo.

Image from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com), used with permission.

Images from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com), used with permission.

The structure of the chloroplast and photosynthetic membranes | Back to Top

Image from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com), used with permission.

Stages of Photosynthesis | Back to Top

Image from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com), used with permission.

Light Reactions | Back to Top

This image is from the University of Minnesota page at http://genbiol.cbs.umn.edu/Multimedia/examples.html.

Images from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com), used with permission.

Images from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com), used with permission.

Dark Reaction | Back to Top

The above image is from http://www-itg.lbl.gov/ImgLib/COLLECTIONS/BERKELEY-LAB/PEOPLE/INDIVIDUALS/index/BIOCHEM_523.html, Ernest OrlandoLawrence Berkeley National Laboratory. " One of the new areas, cultivated both in Donner and the Old Radiation Laboratory, was the study of organic compounds labeled with carbon-14. Melvin Calvin took charge of this work at the end of the war in order to provide raw materials for John Lawrence's researches and for his own study of photosynthesis. Using carbon-14, available in plenty from Hanford reactors, and the new techniques of ion exchange, paper chromatography, and radioautography, Calvin and his many associates mapped the complete path of carbon in photosynthesis. The accomplishment brought him the Nobel prize in chemistry in 1961. (The preceding information was excerpted from the text of the Fall 1981 issue of LBL Newsmagazine.) Citation Caption: LBL News, Vol.6, No.3, Fall 1981 Melvin Calvin shown with some of the apparatus he used to study the role of carbon in photosynthesis."

Image from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com), used with permission.

C-4 Pathway | Back to Top

Image from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com), used with permission.

Image from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com), used with permission.

Images from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com), used with permission.

The Carbon Cycle | Back to Top

Learning Objectives | Back to Top

After completing this chapter you should be able to:

  • Study the general equation for photosynthesis and be able to indicate in which process each reactant is used and each product is produced.
  • List the two major processes of photosynthesis and state what occurs in those sets of reactions.
  • Distinguish between organisms known as autotrophs and those known as heterotrophs as pertains to their modes of nutrition.
  • Explain the significance of the ATP/ADP cycle.
  • Describe the nature of light and how it is associated with the release of electrons from a photosystem.
  • Describe how the pigments found on thylakoid membranes are organized into photosystems and how they relate to photon light energy.
  • Describe the role that chlorophylls and the other pigments found in chloroplasts play to initiate the light-dependent reactions.
  • Describe the function of electron transport systems in the thylakoid membrane.
  • Explain the role of the two energy-carrying molecules produced in the light-dependent reactions (ATP and NADPH) in the light-independent reactions.
  • Describe the Calvin-Benson cycle in terms of its reactants and products.
  • Explain how C-4 photosynthesis provides an advantage for plants in certain environments.
  • Describe the phenomenon of acid rain, and how photosynthesis relates to acid rain and the carbon cycle..

Terms | Back to Top

Review Questions | Back to Top

1. The organic molecule produced directly by photosynthesis is: a) lipids; b) sugar; c) amino acids; d) DNA

2. The photosynthetic process removes ___ from the environment. a) water; b) sugar; c) oxygen; d) chlorophyll; e) carbon dioxide

3. The process of splitting water to release hydrogens and electrons occurs during the _____ process. a) light dependent; b) light independent; c) carbon fixation; d) carbon photophosphorylation; e) glycolysis

4. The process of fixing carbon dioxide into carbohydrates occurs in the ____ process. a) light dependent; b) light independent; c) ATP synthesis; d) carbon photophosphorylation; e) glycolysis

5. Carbon dioxide enters the leaf through ____. a) chloroplasts; b) stomata: c) cuticle; d) mesophyll cells; e) leaf veins

6. The cellular transport process by which carbon dioxide enters a leaf (and by which water vapor and oxygen exit) is ___. a) osmosis; b) active transport; c. co- transport; d) diffusion; e) bulk flow

7. Which of the following creatures would not be an autotroph? a) cactus; b) cyanobacteria; c) fish; d) palm tree; e) phytoplankton

8. The process by which most of the world's autotrophs make their food is known as ____. a) glycolysis; b) photosynthesis; c) chemosynthesis; d) herbivory; e) C-4 cycle

9. The process of ___ is how ADP + P are converted into ATP during the Light dependent process. a) glycolysis; b) Calvin Cycle; c) chemiosmosis;d) substrate-level phosphorylation; e) Kreb's Cycle

10. Once ATP is converted into ADP + P, it must be ____. a) disassembled into components (sugar, base, phosphates) and then ressembled; b) recharged by chemiosmosis; c) converted into NADPH; d) processed by the glycolysis process; e) converted from matter into energy.

11. Generally speaking, the longer the wavelenght of light, the ___ the available energy of that light. a) smaller; b) greater; c) same

12. The section of the electromagnetic spectrum used for photosynthesis is ___. a) infrared; b) ultraviolet; c) x-ray; d) visible light; e) none of the above

13. The colors of light in the visible range (from longest wavelength to shortest) is ___. a) ROYGBIV; b) VIBGYOR; c) GRBIYV; d) ROYROGERS; e) EBGDF

14. The photosynthetic pigment that is essential for the process to occur is ___. a) chlorophyll a; b) chlorophyll b; c) beta carotene; d) xanthocyanin; e) fucoxanthin

15. When a pigment reflects red light, _____. a) all colors of light are absorbed; b) all col;ors of light are reflected; c) green light is reflected, all others are absorbed; d) red light is reflected, all others are absorbed; e) red light is absorbed after it is reflected into the internal pigment molecules.

16. Chlorophyll a absorbs light energy in the ____color range. a) yellow-green; b) red-organge; c) blue violet; d) a and b; e) b and c.

17. A photosystem is ___. a) a collection of hydrogen-pumping proteins; b)a collection of photosynthetic pigments arranged in a thylakjoid membrane; c) a series of electron-accepting proteins arranged in the thylakoid membrane; d. found only in prokaryotic organisms; e) multiple copies of chlorophyll a located in the stroma of the chloroplast.

18. The individual flattened stacks of membrane material inside the chloroplast are known as ___. a) grana; b) stroma; c) thylakoids; d) cristae; e) matrix

19. The fluid-filled area of the chloroplast is the ___. a) grana; b) stroma; c) thylakoids; d) cristae; e) matrix

20. The chloroplast contains all of these except ___. a) grana; b) stroma; c) DNA; d) membranes; e) endoplasmic reticulum

21. The chloroplasts of plants are most close in size to __. a) unfertilized human eggs; b) human cheek cells; c) human nerve cells; d) bacteria in the human mouth; e) viruses

22. Which of these photosynthetic organisms does not have a chloroplast? a) plants; b) red algae; c) cyanobacteria; d) diatoms; e) dinoflagellates

23. The photoelectric effect refers to ____. a) emission of electrons from a metal when energy of a critical wavelength strikes the metal; b) absorbtion of electrons from the surrounding environment when energy of a critical wavelength is nearby; c) emission of electrons from a metal when struck by any wavelength of light; d) emission of electrons stored in the daytime when stomata are open at night; e) release of NADPH and ATP energy during the Calvin Cycvle when light iof a specific wavelength strikes the cell.

24. Light of the green wavelengths is commonly absorbed by which accessory pigment? a) chlorophyll a; b) chlorophyll b; c) phycocyanin; d) beta carotene

25. The function of the electron transport proteins in the thyakoid membranes is ___. a) production of ADP by chemiosmosis; b) production of NADPH by substrate-level phosphorylation; c) pumping of hydrogens into the thylakoid space for later generation of ATP by chemiosmosis; d) pumping of hydrogens into the inner cristae space for later generation of ATP by chemiosmosis; e) preparation of water for eventual incorporation into glucose

26. ATP is known as the energy currency of the cell because ____. a) ATP is the most readily usable form of energy for cells; b) ATP passes energy along in an electron transport chain; c) ATP energy is passed to NADPH; d) ATP traps more energy than is produced in its formation; e) only eukaryotic cells use this energy currency.

27. Both cyclic and noncyclic photophosphorylation produce ATP. We can infer that the purpose of ATP in photosynthesis is to ____. a) supply hydrogen to the carbohydrate; b) supply carbon to the carbohydrate; c)supply energy that can be used to form a carbohydrate; d) transfer oxygens from the third phosphate group to the carbohydrate molecule; e) convert RuBP into PGA

28. The role of NADPH in oxygen-producing photosynthesis is to ____. a) supply hydrogen to the carbohydrate; b) supply carbon to the carbohydrate; c) supply energy that can be used to form a carbohydrate; d) transfer oxygens from the third phosphate group to the carbohydrate molecule; e) convert RuBP into PGA.

29. The dark reactions require all of these chemicals to proceed except ___. a) ATP; b) NADPH; c) carbon dioxide; d) RUBP; e) oxygen

30. The first stable chemical formed by the Calvin Cycle is _____. a) RUBP; b) RU/18; c) PGA; d) PGAL; e) Rubisco

31. The hydrogen in the carbohydrate produced by the Calvin Cycle comes from ___ a.) ATP; b) NADPH; c) the environment if the pH is very acidic; d) a and b; e) a and c

32. The carbon incorporated into the carbohydrate comes from ___. a) ATP; b) NADPH; c) carbon dioxide; d) glucose; e) organic molecules

33. C-4 photosynthesis is so named because _____. a) it produces a three carbon compound as the first stable product of photosynthesis; b) it produces a four carbon compound as the first stable produc of photosynthesis; c) it produces four ATP and four NADPH molecules for carbon fixation.; d) there are only four steps in this form of carbon fixation into carbohydrate.

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Text ©1992, 1994, 1997, 1998, 1999, 2000, 2001, 2007 by M.J. Farabee, all rights reserved. Use for educational purposes is encouraged.

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Chosen Value of the Week 1/30/98

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Photosynthesis -
Part I: The Sun and Light

Not all of the light from the Sun makes it to the surface of the Earth. Even the light that does make it here is reflected and spread out. The little light that does make it here is enough for the plants of the world to survive and go through the process of photosynthesis. Light is actually energy, electromagnetic energy to be exact. When that energy gets to a green plant, all sorts of reactions can take place to store energy in the form of sugar molecules.

Remember we said that not all the energy from the Sun makes it to plants? Even when light gets to a plant, the plant doesn't use all of it. It actually uses only certain colors to make photosynthesis happen. Plants mostly absorb red and blue wavelengths. When you see a color, it is actually a color that the object does NOT absorb. In the case of green plants, they do not absorb light from the green range.

Part II: The Chloroplast

We already spoke about the structure of chloroplasts in the cells tutorials. We want to reinforce that photosynthesis happens in the chloroplast. Within this cell organelle is the chlorophyll that captures the light from the Sun. We'll talk about it in a bit, but the chloroplasts are working night and day with different jobs. The molecules are moved and converted in the area called the stroma.

Part III: The Molecules

Chlorophyll is the magic compound that can grab that sunlight and start the whole process. Chlorophyll is actually quite a varied compound. There are four (4) types: a, b, c, and d. Chlorophyll can also be found in many microorganisms and even some prokaryotic cells. However, as far as plants are concerned, the chlorophyll is found in the chloroplasts. The other big molecules are water (H2O), carbon dioxide (CO2), oxygen (O2) and glucose (C6H12O6). Carbon dioxide and water combine with light to create oxygen and glucose. That glucose is used in various forms by every creature on the planet. Animal cells require oxygen to survive. Animal cells need an aerobic environment (one with oxygen).

Part IV: Light and Dark Reactions

The whole process doesn't happen all at one time. The process of photosynthesis is divided into two main parts. The first part is called the light dependent reaction. This reaction happens when the light energy is captured and pushed into a chemical called ATP. The second part of the process happens when the ATP is used to make glucose (the Calvin Cycle). That second part is called the light independent reaction.

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Seeing Photosynthesis from Space (NASA/GSFC Video)


Useful Reference Materials

Encyclopedia.com:
http://www.encyclopedia.com/topic/photosynthesis.aspx
Wikipedia:
http://en.wikipedia.org/wiki/Photosynthesis
Encyclopædia Britannica:
http://www.britannica.com/EBchecked/topic/458172/photosynthesis


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